1. Field of the Invention
The invention relates to a drive shaft, particularly a longitudinal shaft for motor vehicles, which shaft has at least one hollow shaft section and at least one constant velocity joint, the outer hub of which joint is connected with the hollow shaft section, and which joint is sealed off, with regard to the hollow shaft section, by way of a lid. Furthermore, the invention relates to a constant velocity joint that can be used in such a drive shaft.
2. Description of the Related Art
A constant velocity joint for a drive shaft, of the type stated above, is known from DE 102 09 933 A1. In the case of this joint, which is configured as a counter-track joint, the outer hub is surrounded by an accommodation part, whereby a sealing disk, i.e. a lid, is provided between the accommodation part and the outer hub, which lid is supposed to prevent the penetration of dirt into the joint. In the case of a frontal collision, for example, high axial forces act on the drive shaft, by means of which forces the constant velocity joint can be destroyed, so that the inner hub can penetrate into the hollow shaft connected with the outer hub. In this connection, the lid, which merely serves to seal the joint, does not form any noteworthy resistance, but rather already allows itself to be pushed into the hollow shaft, together with the inner hub, at relatively low forces.
In motor vehicles, the drive shaft is nowadays designed in view of possible crash stresses, among other things, so that the drive shaft absorbs energy and deforms in the case of a high axial force that occurs as the result of an accident, for example. In this connection, the deformation is supposed to take place in such a way, if at all possible, that the drive shaft cannot penetrate into the interior of the vehicle, in order to thereby keep the risk of injury to the occupants low. For this purpose, a drive shaft is proposed in DE 42 27 967 A1, which has a zone demonstrating plastic deformation behavior that can be reproduced in defined manner. This zone is designed in such a manner that the sections of the drive shaft, which is configured as a hollow shaft, fold onto one another and push into one another by regions. In the case of this configuration of a drive shaft, also referred to as a collapsible tube, the drive shaft is deformed, with a high absorption of energy, if a defined axial force is exceeded.
If a drive shaft configured in this manner has a constant velocity joint described above, a rapid increase in the force can occur in the case of a high axial force that occurs as the result of an accident, with a slight deformation path, until the constant velocity joint is destroyed. Afterwards, the inner hub of the constant velocity joint, together with the lid, can be pushed into the hollow shaft, by a certain path distance, with comparatively little force, before the hollow shaft makes contact with the transmission or the differential, for example. Only then will the shaft deform, absorbing a greater amount of force. Because of this increase, drop, and renewed increase in the deformation force, alternating accelerations act on the vehicle occupants, and these can bring about injuries, for example whiplash syndrome, or even more serious injuries.